A power storage apparatus is equipped with switches, such as a relay and a semiconductor switching element, to enhance safety. The switch prevents a power storage device from falling into an overdischarge state or an overcharge state. Such a power storage apparatus is used, for example, as a power source for a vehicle, and is configured to be charged by an alternator of the vehicle. JP 2014-166020 A describes that a voltage generated by an alternator is stepped down by a voltage converter to supply electric power to a load such as a power storage apparatus.